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G-BOXX 2 is born !

Bicyclist

Turbo Monkey
Apr 4, 2004
10,152
2
SB
It would be cool to see an adjustable head angle, from 64-66. That BB height sounds good to me. The design looks killer!
 

htrdoug

Chimp
Nov 25, 2001
66
0
So.Indiana
luelling said:
Thats a cool pic. I like it when you see mountain bike tech used in other industries
I remember seeing a parallelogram setup way back in the seventies on a Kawasaki MX bike tried by the factory riders,and boyeson built a rear swing arm setup that moved the pivot point to effectively the countershaft sprocket,nothing hardly hasn't already been tried.I think the use of chain torque to control suspension action is too much of a benefit to give up on a moto.(think pedal kick on a trials bike)If you notice no one uses a full floating rear brake on a mxer anymore,a little brake drag helps keep the rear wheel under control at times.Amp reaseach's chain torque eliminator went away because it worked backwards of what is most effective in real life riding.
 

EVRAC

Monkey
Jun 21, 2004
757
19
Port Coquitlam, B.C., Canada
Vrock said:
OK, I have figured out a design for a DH bike with a V-Boxx and I'll like to know your opinion... It has 8 inches of travel, the Geo is not finished so I accept sugestions. Right now the HA is 64º, too slack? and the BB Height is 360mm, too low?

3D views will come soon :)
That is HOT!
The third pic looks funny because what is the chance of the rear bottoming while the front is at full extension, eh?
If you lengthened that little swing-link, it would reduce the loads on those bearings. Also, you could experiment with mounting the shock to the downtube. Make sure there is room between the tire and seat at full travel.
I love the "upside-down" rear triangle. I'd been thinking the same thing. I think that's where all this pull shock talk came from, although even if they existed, I'm not sure how you'd implement that.

Anyways, the design looks totally viable and ridable.
Keep up the good work.
 

Wilhelm

Monkey
Aug 10, 2003
444
19
I´m afraid that the (short) linkage plates (e.g. swing link) could be a critical factor of your design, because of the responsing mode of the suspension is a function of (e.g. is limited by) the actual angle (e.g. position) of the swing link. Besides the clean look of the design, to realize big rear wheel travel, other suspension designs seem more promising.
However, keep us informed about the progress of your interesting project.
 

Cave Dweller

Monkey
May 6, 2003
993
0
dw said:
The biggest challenge I see is that it forces companies to use a cookie cutter suspension layout that is unfortunately, (but I think agreed upon by many riders) not the state of the art by todays standards. Also, with unique suspensions being the basis of many mountian bike companies entire marketing plans and design methodologies, it may be a tough sell
dw said:
I can GUARANTEE you that use of dw-link would reduce lap times on a motorcycle in Moto GP or Supercross. You won't have to take my word for it on this for long.
Sorry for this gravedig, but i was thinking about this last night. What you have said here appears to be a contradiction, and i think atrokz has already alluded to this

atrokz said:
If the DW link is being developed for MX use, what is to stop it or a similar system being used for a ID bike? Last time I checked motorcycles dont have derailuers and only have one external......
If you can make the DW link work on a motor bike why couldn't you make it work on a mountain bike? Both a motor or the G-Box have a fixed output sprocket and slack would need to be taken up with some kind of tensioner.

Why wouldn't it work? Shock position maybe?
 

dw

Wiffle Ball ninja
Sep 10, 2001
2,943
0
MV
Cave Dweller said:
Sorry for this gravedig, but i was thinking about this last night. What you have said here appears to be a contradiction, and i think atrokz has already alluded to this



If you can make the DW link work on a motor bike why couldn't you make it work on a mountain bike? Both a motor or the G-Box have a fixed output sprocket and slack would need to be taken up with some kind of tensioner.

Why wouldn't it work? Shock position maybe?
No problem, I can see how that could be confusing. Let me clarify.

The first statement I am talking about the ACTUAL G-Boxx standards as they are proposed now, just the hardware that is shown and being proposed by actual manufacturers. If a gearbox is to be successful, its going to need to be able to accomodate suspension designs like dw-link, vpp, horst link, etc... The current designs dont allow that easily and are intended to be used for single pivot, concentric pivot designs, which are really not preferable in any way (in my opinion at least).

I have applied for patents almost 2 years ago on a linkage suspension system called Orion engineered to tackle the unique situations surrounding motorcycle and non-human powered vehicle use, although it will have huge benefits for human poweed vehicles also. In addition to the new system, dw-link has been adapted for use on motor vehicles also. Can't really comment further right now...

Dave
 

xy9ine

Turbo Monkey
Mar 22, 2004
2,940
353
vancouver eastside
nexus is an 8spd hub developed primarily for city / comfort bike use - ie, not great durability & won't hold up to off road use when rear wheel mounted (apparently they work in frame mount applications though - case in point gt. time will tell re: long term durability in that application).

rohloff is 14spd & bombproof. they are heavy & expensive though.
 

verticult

Chimp
Jan 7, 2005
53
0
this thread is so friggin' funny.. we need to call a honey wagon and pump all the crap out. If the transmission concept can be produced to be reasonable effecient it should have pretty big impact on cycling. for one thing MOST bikes don't get sold because the complexity of shifting to MOST people. Look at the autobike or landrover crap thing.. they outsold most brands in their first year and were basically non-functional. Most freeride and DH riders blow a bunch of derailleurs throughout the season and would welcome this when it works well but it seems like a TDF win is pretty much out of the question. perhaps expecting chainguide manufacturers to start waving the tranny flag is a bit short-sighted. I know I am going to build a bike around this tranny just as soon as I can. I will reserve judgement on this product till I ride that bike.
 

SOil

Chimp
Jun 24, 2005
82
0
Is the 14 speed G-boxx only gripshift?

If so, only when the V-boxx (9spd) or the 7/9 speed G-boxx it'll be possible to use a rapdfire shifter?
 

ÆX

Turbo Monkey
Sep 8, 2001
4,920
17
NM
V-Boxx 9 speed, no
G-Boxx 9 speed, yes, SRAM shifter.
Probably won't be for at least another year.
just got back from the show.

no vboxx to ride at the on dirt demo.:brow:
the only one at the show was all messed up.
cables loose and mot functioning. they said
there were 7 made so far but there are a few
problem in production and looking like if every
thing goes smooth it still will be mid next year!

for me, i can't wait that long so i am not using
them for next years bikes.